Maternal personality and postpartum mental disorders in Japan: the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study.

Personality has been shown to predict postpartum depressive symptoms (PDS) assessed by the Edinburgh Postnatal Depression Scale (EPDS). However, existing studies have not considered the underlying symptom dimensions in the EPDS. We analyzed data from 15,012 women who participated in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Personality was assessed in middle pregnancy using the short-form Eysenck Personality Questionnaire-Revised. PDS were defined as EPDS score ≥ 9 at 1 month after delivery. The EPDS items were further divided into three dimensions: depressed mood, anxiety, and anhedonia. Multiple analyses were conducted to examine the associations of each personality scale with PDS and three dimensions in the EPDS, adjusting for age, parity, mode of delivery, education, income, and social isolation. The prevalence of PDS assessed by the EPDS at 1 month after delivery was 13.1%. Higher neuroticism scores were associated with PDS (odds ratio [OR], 2.63; 95% confidence interval [CI], 2.48 to 2.79) and all three dimensions (all p < 0.001). Lower extraversion scores were associated with PDS (OR, 0.74; 95% CI, 0.70 to 0.78) and all three dimensions (all p < 0.001). Lower psychoticism scores were associated with PDS (OR, 0.89; 95% CI, 0.85 to 0.94) and anxiety (p < 0.001), but not with depressed mood (p = 0.20) or anhedonia (p = 0.92). In conclusion, higher neuroticism and lower extraversion were associated with PDS and the three underlying dimensions in the EPDS, while lower psychoticism was associated with anxiety, but not with depressed mood or anhedonia.